It is known in the art that a paper-like filter having functions to collect dust and to deodorize is configured in a pleated shape so as to increase its surface area, thereby improving its abilities to collect and capture dust and to deodorize, while reducing pressure loss. JPH10-43530 A has proposed an air cleaning filter utilizing a polyurethane form which has a three-dimensional network structure comprising of fine cells on one or both side(s) thereof.
JPH10-43530 A has further proposed a filter in which the polyurethane foam carries absorbent particles such as active carbon. However, the amount of the absorbent particles is relatively small, so that lack of deodorizing feature might occur in some instances.